[Serusers] Cannot capture call status in failure route

[Zeus Ng]

> The root reason is that 'status' is not intended for use in 
> failure_route. (I hope we never advertised it was.) We should 

No you didn't advertise it. It's only my common sense of assuming 'status'
is also available in failure_route got it wrong. I should never do that.
Indeed, there are a couple of functions in the TM module which have no
documentation. I understand you guys are busy and will try digging in the
code for answer. I wouldn't brother you unless I ran into situation like
this. However, would you mind describing what t_forward_noack_uri() and
t_write_req() does and some example scripts.

> obviously make it impossible to avoid confusion. I think that 
> enabling t_check_status from reply_route and removing 
> 'status' will do it.

Before you go on removing 'status', can you confirm the question in the next
paragraph?

> 
> Note there is a great difference between what status and 
> t_check_status do. 'status' refers to currenlty received 
> reply in onreply_route. failure_route is very different -- 
> failure_route returns to processing of the original request, 
> with which several replies may be associated. t_check_status 
> thus first does a branch picking process, selects 
> a branch SER would use if you did nothing else, and that's 
> what you receive.

Does that mean t_check_status is parallel forking safe in reply_route? I
wouldn't want a DND from a client in a group pickup affect the end result of
the call.